#include<iostream>

using namespace std;

int cmmdc(int a[100], int s, int d)
{ if(s==d) return a[s];
  else 
  { int x,y;
    x=cmmdc(a,s,(s+d)/2);
    y=cmmdc(a,(s+d)/2+1,d);
    while(x!=y)
       if(x>y) x=x-y;
       else y=y-x;
    return x;   
  }    
}

int main()
{
    int a[100],n,i;
    cin>>n;
    for(i=1;i<=n;i++) cin>>a[i];
    cout<<cmmdc(a,1,n);
    system("pause");
    return 0;
}